Electrodynamic braking devices are known in different configurations.
U.S. Pat. No. 6,236,177 B1 describes a braking and control circuit for a universal motor, in which, on the one hand, a first switching means (triac) for operating the motor is connected in series with the motor, and, on the other hand, a second switching means (triac) for braking the motor is connected parallel to the armature, wherein the armature is arranged between the field winding. During the motor mode, the second switching means parallel to the armature is not conductive, and during the braking mode both the first switching means and the second switching means are actuated.
EP 0 578 366 A2 describes a braking device for universal motors, in which switching means are used to connect and/or disconnect the field winding and the rotor winding to and respectively from the power grid, wherein the switching means have positions in which in the first position the rotor winding and the field winding are connected to the power grid, and in the second position the rotor winding is short-circuited and the power grid is connected only to the field winding.
DE 103 17 636 A1 describes a braking device for a universal motor, in which a short-circuit switch (triac) is provided for short-circuiting the armature winding during the braking mode, wherein the short-circuit switch has a control input for determining its switched state, and the control input of the short-circuit switch is connected to a control unit in order to carry out phase-gating control of the short-circuit switch during the braking mode in order to avoid sparking.